|Effects of nanoparticles on the stability of polymer fibers|
: 350 : 2018.11.23 00:00
|PHYSICAL REVIEW E|
|Kwon, T (Kwon, Taejin) ; Sung, BJ (Sung, Bong June) 2018.10.31|
Effects of nanoparticles on the stability of polymer fibers
Polymer fibers, promising materials for tissue engineering and stretchable electronics, are intrinsically unstable due to their large surface-to-volume ratio. Recent experiments revealed that the addition of nanoparticles (NPs) to polymer fibers might enhance their stability. The addition of NPs, however, sometimes increases surface tension, which may facilitate the structural disruption of polymer fibers to polymer globules. It remains, therefore, elusive how NPs would affect the stability and the structural disruption of polymer fibers. In this work, we perform molecular dynamics simulations for polymer fibers with NPs of different types of intermolecular interactions. We prepare unstable polymer fibers that disrupt spontaneously into globules without NPs. We find that upon the addition of NPs, the structural disruption of unstable polymer fibers is hindered and the time (tau(b)) taken for the fibers to disrupt to globules is increased. This indicates that the free energy barrier for the transition between the fiber and the globule would be increased due to NPs. The mechanism for the stability enhancement differs for NPs of different intermolecular interactions. When the interaction between polymers and NPs is quite attractive, NPs are located mostly at the center of the fiber around the axis and slow down the polymer mobility. On the other hand, when the interaction between polymers and NPs is not attractive, NPs are likely to be located at the surface of polymer fibers. When NPs are located at the fiber center, tau(b) increases with a decrease in temperature. On the other hand, tau(b) decreases with a decrease in temperature when NPs are located at the fiber surface.